Analytical study about the impact of multipath propagation on UHF-RFID ranging techniques

Given the narrow bandwidth of UHF-RFID it is not possible to separate the different signal paths apart. In this paper the SNR was derived, necessary for any nonlinear super-resolution algorithms. As long as these SNR levels are not met, any evaluation method will give a weighted mean of all the individual paths that exist in the perceived channel. Evaluation methods that use only one of “RSSI” and “phase” will even be worse. In order to open the possibilities of multipath resistant single-antenna ranging to the field of UHF-RFID applications new regulations or technologies with greater bandwidths are unavoidable.